Gun control mechanism



Jan. 1942. F. J. TAlRls ETAL GUN CONTROL MEC HANISM Filed Aug. 15, 1939 2 Sheets-Sheet 1 1942- F. J.TARR IS ET AL GUN CONTROL MECHANISM Filed Aug. 15, 1939 2 Sheets-Sheet 2 Patented Jan. 27, 1942 I 7 2,271,445 GUN CONTROL MECHANISM Frederick John Tarris and Daniel Webb, London,

England, assignors to The India-Rubber, Gutta Percha & Telegraph Works Company, Limited,- London, England, a British company Application August 15, 1939, Serial No. 290,168

In Great Britain August 25, 1938 2 Claims. (or 39-315) The present invention comprises improve- .ments in or relating to gun control mechanisms and has for object the provision of such a mechanism serving to secure a safe operation of the According to the invention there is provided a gun control mechanism for a movably mounted gun comprising gun actuating means operatively connected to a control device therefor in com- 7. to aircraft gun control mechanisms in which case the main control device for the gun actuatingmeans is conveniently in the form of a remote control for the gun, and it is then the purpose of the invention to provide means to prevent the firing of the gun when the gun barrel is in some position of alignment at which damage to the aircraft might result, for example when the gun of a gun turret lowered from the mid-portion of the aircraft fuselage is pointed upwardly or rearwardly in a direction to damage the fuselage or tail of the aircraft.

. In order that the invention may be more clearly understood, one constructional example of the invention employed in the manner last referred to, will be described with reference to the accompanyine drawings, in which- Flgure 1 ls a diagrammatic view,- partly in section. and not to scale, of a hydraulic gun control mechanism;

Figure 2 is a diagrammatic view in side elevation and partly in section, of a gun and gun 'mounting conveniently employed with the gun control mechanism shown in Figure '1;

Figure 3 is a plan view of the gun mounting shown in the lower part of Figure 2;

Figure 4 is a plan view of a control valve employed in the mechanism shown in Figure 1,

and

Figure 5 is a sectional view. looking in the Like reference numerals are employed to denote'like parts in the various figures of the drawings.

direction of the arrows on the line 5-5 of Fig- The hydraulic gun control mechanism shown in Figure 1 comprises a reservoir for hydraulic liquid represented diagrammatically and not to scale at l0 and connected by a hydraulic feed line llto a pump similarly represented at l2. When the invention is applied to guns mounted on aircraft, the pump it will be driven from an aircraft engine, but the pump is in any case preferably motor driven. The pump I2 is connected to a delivery line orhydraulic pressure supply line l3 from which a branch connection N passes to a hydraulic accumulator l5 having an outlet connection It passing to a valve casing ll of a main control valve. An outlet line 18 from the valve casing l1 passes to a further valve casing IQ of an auxiliary control valve having an outlet 20 connected as indicated at 2| to a piston and cylinder device 22 serving on operation by hydraulic pressure supplied thereto for effecting actuation of a gun 23, for example, a machine gun, such as an aircraft gun. Return connections 24 and 25 pass respectively from the valve casings l9 and II to a main return conduit 26 of a hydraulic system, the conduit 26 being connected as indicated by the line 21 to the reservoir l0. T

It will be appreciated that the hydraulic system which has been described is substantially similar to the gun control hydraulic system described in the complete specification of British Patent No. 488,489, (corresponding to the U. S. Patent application Serial No. 170,710), and the main control valve housed in the valve casing I! may be operated by means of a subsidiary hydraulic line as described in the aforesaid patent specification or it may be efiected by means of a Bowden cable or other. mechanical connection 28 operable from a position occupied by the gun operator. The valve casing l'l houses a valve member 29 serving alternatively to place the feed and return lines It and 25 in communication with the outlet line Hi, the valve member 29 normally being maintained by the spring 30 in a position in which the feed line I6 is closed and the return line 25 in communication with the outlet line l8. Operation of the valve member 29 to secure actuation of the gun 23 will thus be eflected by means of the mechanical connection 28 actuated against the action of the spring 30 to bring the valve member 29 to the position represented in Figure 1.

The present invention affords also means to control-the supply of pressure fluid to the gun actuating the device 22 according to the position of alignment of the gun 23. Such means in the present example comprises the auxiliary control valve housed in the valve casing I9 and having a valve member 3|. The valve member 3| also controls the supply of pressure fluid to the gun actuating means 22 and, similarly to the main control valve, serves alternatively to place the return line. 24 on the feed line I8 in communication with the outlet connection and 2|. The valve member 3|, however, is normally maintained by means of the spring 32 in a position in which the return line 24 is closed and the supply line I8 maintained in communication with the outlet connection 20 as shown in Figure -1.

It will be noted that the main control valve housed in the valve casing I1 and the auxiliary controlvalve housed in the valve casing I9 are each disposed in the feed line to the gun actuating device 22 but it is not necessary for thesetwo valves to be disposed in any particular or sequence in the said feed line.

The auxiliary control valve housed in the casing I9, however, will be controlled by the interaction of cooperating parts respectively associated with the gun mounting and with the gun barrel. As shown in Figure 2, for example, the gun 23 is mounted for pivotal movement about a horizontal pivot 33 and is connected by a pivoted link 34 to a cam 35 slidably mounted in a guide 36 for vertical movement in the guide in accordance with pivotal movement of the gun 23 about the pivot 33. The gun pivot 33 will also be carorder,

.ried in bearings, not shown in the drawings, as-

sociated with the rotatable mount 31 with which the guide 36 is integrally formed, the mount 31 being rotatable on a central column 38 having 3 a base 39 secured for example to a suitable part of an aircraft. A guide pin 40 is carried by the mount 31 to engage and to be guided in a groove 4| provided in column 38. The valve casing I9 is conveniently mounted at the top of the column 38 so that a projection or a cam follower 42 is disposed in contact with the surface of the slidable and rotatable cam 35. The cam follower 42 is connected to that end of the valve member 3| remote from the spring 32. The cam surface of the cam 35 will thus slide in a vertical direction according to the elevation of the gun 23 and will also move with rotation of the mount 31 in accordance with any traversing movement of the gun 23. The cam surface will be such that the cam follower 42 remains in engagement with the surface during all possible positions of adjustment and alignment of the gun 23 and will also afford projections at positions on the surface engaged by the cam follower when the gun is in positions of alignment at which firing of the gun is undesirable, for example, when firing of the gun will serve to damage an aircraft.v

in which it is mounted. The cam projections serve to effect a movementgof the valve member 3| preventing the supply of hydraulic liquid under pressure to the gun actuating means 22 and thus preventing also operation of the gun if the main control valve member 23 is-then actuated. The movement of the valve member 3| enacted by the cam projections is also such as to cause a cessation of firing of the gun since a hydraulic connection is established between the gun actuating means 22 and the hydraulic exhaust or return line, and firing similarly recommences automatically at a suitable point in the movement of the gun if the main control valve is actuated during the whole of such movement. The cam surface of the cam 35 shown in Figures 2 and 3 is in the form of a partial cylin-- der and carries cruciform projections 33 and 44 which may serve for example to prevent a gun 23 normally directed towards the rear of an aircraft from damaging tail planes or rudder mechanism of the craft.

The piston and cylinder device 22 for effecting actuation of the gun 23 may be such as to actuate the gun trigger mechanism and may be similar to the device described in the complete specification of British Patent No. 500,725, (corresponding to U. S. Patent application Serial No. 217,046). Any alternative equivalent device may, however, be employed and similarly any preferred form of hydraulic accumulator represented at l5 may be employed in the present arrangement.

The main control valve housed in the valve casing I1 is shown in greater detail in Figures 4 and 5 in which the mechanical connection 28 is represented by operating cables secured to a cross-head carried by a stem 45 having a head 46 to effect movement of the double-ended piston valve member 29 subject to the action of the spring 30 disposed to surround the stem 45 on that side of the valve member 29 remote from the head 46. The stem 45 passes slidably ough a suitable sealing gland 41. The valve member 29 controls the interconnection as described above of apertures 48 in a cylindrical sleeve 49 carried in the valve casing I1. The apertures 48 communicate with annular grooves 50 in the central bore of the valve casing II, which annular grooves respectively communicate with the conduit connections I6, I8 and 25. The central bore of the valve casing I1 is closed by an end plug 5|. In the case of the auxiliary control valve housed in the casing I9 a valve structure similar to that shown in Figures 4 and 5 will be employed, but with the disposition of the valve spring 32 on that side of the valve member 3| remote from that of the spring 3|) relative to the valve member 29. The valve stem 45 will also carry the cam follower 42 in place of the mechanical continuous circulation of hydraulic liquid is maintained in a circuit in which the control valves are disposed to be normally open but closed when operation of the gun is desired so as to ensure the building up of a hydraulic pressure in the circuit on that side of the valve from which hydraulic fluid normally passes to the valve. The conduit connection for the actual gun actuating means will also be disposed on this side or the control valve or valves in the hydraulic circuit.

Modification of the apparatus which has been described may also be effected in that the auxiliary control valve may be provided with means to eflect a snap-over action to give an'instantaneous response to the movement of adjustment The invention is also applicable to a hydraulic system in which a V trol valve II is opened or closed can be spring assisted once the cam follower is past the deadcentre of its movement in either direction,

We claim: 1. Gun flre control mechanism comprising in combination gun flre actuating means operable by fluid pressure, a fluid pressure supply line leading to the gun flre actuating mechanism, a

fluid pressure return line, a main control valve included in the fluid supply line and controlling respectively ports. communicating with the gun flre actuating mechanism and with the re turn line, an auxiliary valve similarly interposed in the supply line to control also ports leading to the gun fire actuating mechanism and to the return line respectivelma cam which is formed on the surface of an otherwise substantially cylindrical cam carrier and is operatively connected with the gun to move in company therewith, a cam follower cooperating with said- 2. Gun flre control mechanism comprising in combination gun flre actuating mechanism operable by fluid pressure,- a fluid pressure supply line leading to-the gun flre actuating mechanism, a fluid pressure return line, a main control valve included in the fluid supply line and controlling respectively ports communicating with the gun fire actuating mechanism and with the return line, an auxiliary valve similarly interposed in the supply line to control also ports leading to the gun fire actuating mechanism and to the return line respectively, a-cam which is formed on the surface of an otherwise substantially cylindrical cam carrier and is operatively connected with the gun to be moved it in company therewith, a cam follower directly carried by the auxiliary valve, and means to mount. the cam carrier for movement in both axial and circumferential directions in company with elevational and traversing movements imparted to the gun respectively whereby movement of the gun operates to control movements of the auxiliary valve.

FREDERICK JOHN TARRIS. DANIEL WEBB. 

